我写了一个节目“MadProgrammer问我” 但我收到了错误 这是代码：
import java.util.Timer;
import java.util.TimerTask;
import java.awt.Toolkit;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
//import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
/**
*
* @author Windows 8 Java
*/
public class NewJFrame extends javax.swing.JFrame {
Toolkit toolkit;
Timer timer;
public NewJFrame() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
/*toolkit = Toolkit.getDefaultToolkit();
timer = new Timer();
timer.schedule(new RemindTask(),
0, //initial delay
1*1000); //subsequent rate*/
}
/*class RemindTask extends TimerTask {
int numWarningBeeps = 3;
public void run() {
if (numWarningBeeps > 0) {
toolkit.beep();
System.out.format("Beep!%n");
numWarningBeeps--;
} else {
toolkit.beep();
System.out.format("Time's up!%n");
//timer.cancel(); //Not necessary because we call System.exit
System.exit(0); //Stops the AWT thread (and everything else)
}
}
}
*/
public class TestPane extends JPanel {
private JTextField field;
private JButton button;
private int tick;
private Timer timer;
public TestPane() {
field = new JTextField(10);
field.setEditable(false);
button = new JButton("Start");
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
button.setEnabled(false);
tick = 0;
timer.start();
}
});
timer = new Timer(1000, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
field.setText(Integer.toString(++tick));
if (tick > 4) {
timer.stop();
button.setEnabled(true);
}
}
});
timer.setInitialDelay(0);
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
add(field, gbc);
add(button, gbc);
}
}
/**
* Creates new form NewJFrame
*/
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/*
* If Nimbus (introduced in Java SE 6) is not available, stay with the
* default look and feel. For details see
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
System.out.format("About to schedule task.%n");
new NewJFrame();
System.out.format("Task scheduled.%n");
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
// End of variables declaration
}
我正在使用netbeans 错误如下：
in " `public class TestPane extends JPanel`"
at "`timer.start();`"
at " `timer = new Timer(1000, new ActionListener() {`"
at "`timer.stop();`"
and at "`timer.setInitialDelay(0);`"
请帮助 提前致谢 达克士
答案 0 :(得分：3)
您的导入存在问题：
new Timer(1000, new ActionListener()
此构造函数仅适用于 javax.swing.Timer 。
但你实际上导入 java.util.Timer
import java.util.Timer;